Perspectives on the unusual electrochemical corrosion of Nickel Aluminum Bronze (NAB) alloy fabricated through laser-powder bed fusion additive manufacturing

This research delves into the passivation and electrochemical corrosion response of as-printed and annealed LPBF NAB, comparing their performance with wrought NAB counterparts. The results unveil that the interplay between microstructural uniformity, higher aluminum content, residual stress, and the presence of martensitic nanotwins substantially enhances the integrity of the corrosion film and improves the uniform corrosion resistance of as-fabricated NAB. Nonetheless, this combination adversely impacts the localized corrosion resistance. Remarkably, annealing, despite its detrimental effect on passivation and uniform corrosion behavior, ameliorates resistance to localized attacks. In contrast, the wrought equivalents exhibit inferior electrochemical corrosion performance across all experimental conditions.